Searching for bioactive substances from some compositae weeds

Abstract

In the search for bioactive substances from four weed species in compositae family; Eupatorium adenophorum Spreng., Eupatoruim odoratum Linn., Ageratum conyzoides Linn. and Sphaeranthus africanus Linn., the preliminary results revealed that the crude extract of the aerial part of E. adenophorum displayed the most attractive biological activities. Further solvent fractionation of E. adenophorum and biological tests exhibited that dichloromethane, ethyl acetate and butanol crude extracts showed rice growth inhibition activity 95.35%, 90.05% and 100% at concentration 0.1 g, respectively and displayed cytotoxicity against brine shrimp (Artemia salina Linn.) with LC50 value of 10.43, 12.56 and 10.02, respectively at 24 h. The separation of dichloromethane, ethanol, ethyl acetate and butanol crude extracts by means of chromatograph led to the isolation of 6 substances. They were found to be a mixture of long chain alcohols, stigmasterol, a mixture of long chain carboxylic acids, a mixture of long chain esters, protocatechuic acid and steroid glycoside. Protocatechuic acid displayed high bioactivity as plant growth inhibitor 92.30% at dose level 1000 ppm.